False saucer over Palaiseau explained by a radar installation

Summary

On 2 February 2002, at around 19:40, a family driving through Essonne spotted a luminous saucer-shaped object above a forest. It had a dome on top, white lights along its edge, an estimated diameter of 15 metres, and made no noise. They lost sight of it after a bend in the road.

Originally opened as a D case, the investigation was reopened when a water tower was suggested as the source. Further analysis ruled that out and determined the object was most likely a secondary radar installation associated with Orly airport. The radar's location matched the witnesses' description, leading GEIPAN to reclassify the case as B — a clear example of how a conventional installation can cause visual confusion.